AMS June science highlights

June 12, 2009

Following are story ideas and tips about upcoming AMS meetings, papers in our peer-reviewed journals, and other happenings in the atmospheric and related sciences community.

Advances and Challenges at the National Hurricane Center. With hurricane season underway, a paper in the April issue of the AMS’ Weather and Forecasting is valuable resources for learning about the current workings and state of the nation’s hurricane warning program, and highlights recent improvements and the enabling science and technology. The National Hurricane Center issues analyses, forecasts, and warnings over large parts of the North Atlantic and Pacific Oceans, and in support of many nearby countries. Advances in observational capabilities, operational numerical weather prediction, and forecaster tools and support systems over the past 15󈞀 years have enabled the center to make more accurate forecasts, extend forecast lead times, and provide new products and services. Important limitations, however, persist. The paper also includes a look ahead at opportunities to address challenges. For a copy contact Stephanie Kenitzer.

Fifty Years of Climate Trends. It is no secret that climate trends exhibit distinct seasonality and regionality. A paper in the May issue of the AMS Journal of Climate takes a closer look at the causes of the seasonality and regionality of those trends, with a focus on the cooling and wetting trends in the central United States during late summer and fall. In particular, the authors examined the link between the seasonality and regionality of the climate trends over the United States and the leading patterns of sea surface temperature (SST) variability, including a global warming (GW) pattern and a Pacific decadal variability (PDV) pattern. The results show that the observed seasonal and spatial variations of the climate trends over the United States are to a large extent explained by changes in SST. Among the leading patterns of SST variability, the PDV pattern plays a prominent role in producing both the seasonality and regionality of the climate trends over the United States. In particular, it is the main contributor to the apparent cooling and wetting trends over the central United States. These results highlight the important contributions of decadal and multidecadal variability in the Pacific and Atlantic in explaining the observed seasonality and regionality of the climate trends over the United States during the period of 1950�. For a copy of the paper, contact Stephanie Kenitzer.

Here to Stay? How long will anthropogenic CO2 emissions linger? A paper in the May issue of the AMS Journal of Climate examines multimillennial simulations using a fully coupled climate?carbon cycle model to assess the persistence of the climatic impacts of anthropogenic CO2 emissions. The researchers found that the time required to absorb anthropogenic CO2 strongly depends on the total amount of emissions; for emissions similar to known fossil fuel reserves, the time to absorb 50% of the CO2 is more than 2000 years. The long-term climate response appears to be independent of the rate at which CO2 is emitted over the next few centuries. Results further suggest that the lifetime of the surface air temperature anomaly might be as much as 60% longer than the lifetime of anthropogenic CO2 and that two-thirds of the maximum temperature anomaly will persist for longer than 10 000 years. This suggests that the consequences of anthropogenic CO2 emissions will persist for many millennia. For a copy of the paper, contact Stephanie Kenitzer.